Fluorite, Graymont Quarry, Genoa, Ohio
Contributed by: Chris Clemens
minID: TW8-YPV
Date: Apr 18th, 2026
Locality: Graymont Dolime (OH) Inc. Quarry, Clay Township, Ottawa County, Ohio, USA (See on Mindat)
Size: 41 x 25 x 55 mm
Weight: 55 g
Description:
This is a brightly fluorescent cluster of root beer brown colored fluorite cubes, with white bladed celestine crystals, from the Graymont Quarry, Genoa, Ottawa County, Ohio. The bright fluorescent response is activated by organic inclusions in the fluorite crystals. Many of the root beer fluorites from the Findlay Arch district of northwestern Ohio show a similar fluorescent response under UV, but this specimen is the brightest I have encountered.
The Graymont Quarry (aka Graymont Dolime Quarry, Genoa Quarry) is a well-known producer of beautiful fluorite specimens. This active quarry has been in operation since the late 1800's and produces lime products and construction aggregate.
As is typical for root beer fluorite from northwest Ohio, this specimen shows its brightest fluorescent response under longwave UV (365 nm). Note that the response is warmer than seen under shortwave UV. Pale yellow phosphorescence is seen following exposure to longwave UV (365 nm).
Originally posted by Chris Clemens on Nature's Rainbows in 2020.
Summary of luminescence responses:
Fluorite (Mindat) (RRUFF)
- Fluorescence under Longwave (365nm LED) UV light: White
- Afterglow after exposure to Longwave (365nm LED) UV light: Yellow
- Fluorescence under Shortwave (254nm Lamp/Mercury) UV light: White
- Afterglow after exposure to Shortwave (254nm Lamp/Mercury) UV light: Blue